scholarly journals Physics of magnetized dusty plasmas

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Andre Melzer ◽  
H. Krüger ◽  
D. Maier ◽  
S. Schütt
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Dusty Plasma ◽  
Acoustic Waves ◽  
Dusty Plasmas ◽  
Plasma Properties ◽  
Fundamental Parameters ◽  
Wake Field ◽  
Magnetized Dusty Plasma ◽  
Dust Component

AbstractIn this review, we summarize recent advances in the field of dusty plasmas at strong magnetic fields. Special emphasis is put on situations where experimental laboratory observations are available. These generally comprise dusty plasmas with magnetized electrons and ions, but unmagnetized dust. The fundamental parameters characterizing a magnetized (dusty) plasma are given and various effects in dusty plasmas under magnetic fields are presented. As examples, the reaction of the dust component to magnetic-field modified plasma properties, such as filamentation, imposed structures, dust rotation, nanodusty plasmas and the resulting forces on the dust are discussed. Further, the behavior of the dust charge is described and shown to be relatively unaffected by magnetic fields. Wake field formation in magnetized discharges is illustrated: the strength of the wake field is found to be reduced with increased magnetic field. The propagation of dust acoustic waves in magnetized dusty plasmas is experimentally measured and analyzed indicating that the wave dynamics are not heavily influenced by the magnetic field. Only at the highest fields ($$B> 1$$ B > 1  T) the wave activity is found to be reduced. Moreover, it is discussed how dust-cyclotron waves might be used to indicate a magnetized dust component. Finally, implications of a magnetized dusty plasma are illustrated.

The magnetized dusty plasma experiment (MDPX)

2015 ◽  
Vol 81 (2) ◽  
Author(s):  
E. Thomas ◽  
U. Konopka ◽  
D. Artis ◽  
B. Lynch ◽  
S. Leblanc ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Dusty Plasma ◽  
Vacuum Chamber ◽  
Superconducting Magnet ◽  
Dusty Plasmas ◽  
Magnetized Dusty Plasma ◽  
Research Activities ◽  
Plasma Experiment ◽  
Plasma Device ◽  
Main Components

The magnetized dusty plasma experiment (MDPX) is a newly commissioned plasma device that started operations in late spring, 2014. The research activities of this device are focused on the study of the physics, highly magnetized plasmas, and magnetized dusty plasmas. The design of the MDPX device is centered on two main components: an open bore, superconducting magnet that is designed to produce, in a steady state, both uniform magnetic fields up to 4 Tesla and non-uniform magnetic fields with gradients of 1–2 T m−1and a flexible, removable, octagonal vacuum chamber that provides substantial probe and optical access to the plasma. This paper will provide a review of the design criteria for the MDPX device, a description of the research objectives, and brief discussion of the research opportunities offered by this multi-institution, multi-user project.

Relaxed states in electron-depleted electronegative dusty plasmas with two-negative ion species

2013 ◽  
Vol 80 (1) ◽  
pp. 59-65 ◽  
Author(s):  
M. Iqbal
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Dusty Plasma ◽  
Negative Ions ◽  
Dusty Plasmas ◽  
Numerical Results ◽  
Negative Ion ◽  
Inertial Forces ◽  
Plasma Species ◽  
Ion Species

AbstractThe relaxation of an electron-depleted electronegative dusty plasma with two-negative ions is investigated. When the ratio of canonical vorticities to corresponding flows of all the plasma species is the same and all inertial and non-inertial forces are present, the relaxed state appears as a double Beltrami magnetic field which is the superposition of two force-free relaxed states. The numerical results show that highly diamagnetic relaxed magnetic fields can be obtained by controlling the flow and vorticities through a single Beltrami parameter. The study is useful to investigate the creation of diamagnetic plasma configurations which are considered to be very important in the context of nuclear fusion.

scholarly journals The effects of surface fossil magnetic fields on massive star evolution: III. The case of τ Sco

2021 ◽  
Author(s):  
Z Keszthelyi ◽  
G Meynet ◽  
F Martins ◽  
A de Koter ◽  
A David-Uraz
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Massive Star ◽  
Slow Rotation ◽  
Single Star ◽  
Surface Magnetic Field ◽  
Fundamental Parameters ◽  
Chemical Enrichment ◽  
Star Models ◽  
Nitrogen Excess

Abstract τ Sco, a well-studied magnetic B-type star in the Uτer Sco association, has a number of surprising characteristics. It rotates very slowly and shows nitrogen excess. Its surface magnetic field is much more complex than a purely dipolar configuration which is unusual for a magnetic massive star. We employ the cmfgen radiative transfer code to determine the fundamental parameters and surface CNO and helium abundances. Then, we employ mesa and genec stellar evolution models accounting for the effects of surface magnetic fields. To reconcile τ Sco’s properties with single-star models, an increase is necessary in the efficiency of rotational mixing by a factor of 3 to 10 and in the efficiency of magnetic braking by a factor of 10. The spin down could be explained by assuming a magnetic field decay scenario. However, the simultaneous chemical enrichment challenges the single-star scenario. Previous works indeed suggested a stellar merger origin for τ Sco. However, the merger scenario also faces similar challenges as our magnetic single-star models to explain τ Sco’s simultaneous slow rotation and nitrogen excess. In conclusion, the single-star channel seems less likely and versatile to explain these discrepancies, while the merger scenario and other potential binary-evolution channels still require further assessment as to whether they may self-consistently explain the observables of τ Sco.

Dust-acoustic waves in a magnetized dusty plasma

1998 ◽  
Vol 5 (3) ◽  
pp. 828-829 ◽  
Author(s):  
M. Salimullah ◽  
M. Salahuddin
Keyword(s):  
Dusty Plasma ◽  
Acoustic Waves ◽  
Dust Acoustic Waves ◽  
Magnetized Dusty Plasma ◽  
Dust Acoustic

Magnetoacoustic modes in a magnetized dusty plasma

1995 ◽  
Vol 53 (3) ◽  
pp. 317-334 ◽  
Author(s):  
N. N. Rao
Keyword(s):  
Acoustic Wave ◽  
Dusty Plasma ◽  
Acoustic Waves ◽  
Acoustic Mode ◽  
Dust Particles ◽  
Ion Acoustic Wave ◽  
Magnetized Dusty Plasma ◽  
Magnetoacoustic Waves ◽  
Component Plasma ◽  
Density Perturbations

The existence of various types of (fast) magnetoacoustic modes in different frequency regimes in a magnetized dusty plasma consisting of electrons, ions and dust particles is investigated. The analysis is carried out using an effective two-fluid MHD-like model which allows for the non-frozen motion of the component fluids. For frequencies much smaller than the dust particle gyro- frequency, we obtain a magnetoacoustic mode that is a generalization of the usual compressional fast hydromagnetic wave in an electron—ion plasma. In the higher-frequency regimes, we show the existence of two new types of modes called ‘Dust-magnetoacoustic waves’. Both modes are accompanied by compressional magnetic field and plasma number density perturbations, and are the electromagnetic generalizations of the dust-acoustic waves in an unmagnetized dusty plasma with thermal electrons and ions. For a two- component plasma, all three modes degenerate into the same fast magneto- acoustic wave found in the usual electron—ion plasmas. We also obtain another novel type of magneto-acoustic mode called a ‘dust—ion-magneto- acoustic wave’, which is an electromagnetic generalization of the dust—ion- acoustic wave. The dispersion relations as well as the frequency regimes for the existence of the various modes are explicitly obtained. An alternative derivation of the relevant governing equations using an approach similar to that employed in so-called ‘electron magnetohydrodynamics’ (EMHD) is also presented.

Effects of dust grain charge fluctuation on an obliquely propagating dust acoustic solitary potential in a magnetized dusty plasma

2000 ◽  
Vol 63 (2) ◽  
pp. 191-200 ◽  
Author(s):  
A. A. MAMUN ◽  
M. H. A. HASSAN
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Dusty Plasma ◽  
Finite Amplitude ◽  
Reductive Perturbation Method ◽  
Charge Fluctuation ◽  
Dust Grains ◽  
Magnetized Dusty Plasma ◽  
Dust Acoustic ◽  
Dust Grain

Effects of dust grain charge fluctuation, obliqueness and external magnetic field on a finite-amplitude dust acoustic solitary potential in a magnetized dusty plasma, consisting of electrons, ions and charge-fluctuating dust grains, are investigated using the reductive perturbation method. It is shown that such a magnetized dusty plasma system may support a dust acoustic solitary potential on a very slow time scale involving the motion of dust grains, whose charge is self- consistently determined by local electron and ion currents. The effects of dust grain charge fluctuation, external magnetic field and obliqueness are found to modify the properties of this dust acoustic solitary potential significantly. The implications of these results for some space and astrophysical dusty plasma systems, especially planetary ring systems and cometary tails, are briefly mentioned.

The Harris sheet in a dusty plasma

2010 ◽  
Vol 77 (1) ◽  
pp. 31-37 ◽  
Author(s):  
SAMUEL A. LAZERSON
Keyword(s):  
Current Sheet ◽  
Dusty Plasma ◽  
Nonlinear Differential Equations ◽  
Sheet Thickness ◽  
Dusty Plasmas ◽  
Great Utility ◽  
Highly Nonlinear ◽  
Dust Component ◽  
Great Relevance ◽  
A Current

AbstractIn 1962 E. G. Harris published a solution to the problem of a current sheet separating regions of oppositely directed magnetic field in a fully ionized plasma. The resulting solution has become known as the ‘Harris sheet’ and has been of great utility to the plasma physics community. In this paper, the footsteps of Harris are retraced with the addition of a multiply charged massive dust component. A set of highly nonlinear differential equations for a current sheet in a dusty plasma are presented. An analytic solution, similar to that of Harris, is found for the depleted electron regime. This solution is of great relevance to many astrophysical and laboratory dusty plasmas. Current sheet thickness and asymptotic field strength are calculated for various dusty plasma environments.

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